1. Field of the Invention
This invention relates generally to a dispensing closure cap for containers, and more particularly to a twist look adjustable metering dispensing closure cap which has more than one dispensing position and provides positive indications of the cap position during manipulation thereof.
2. Description of the Prior Art
Dispensing closure caps for containers typically are of the push-pull or threaded screw type and generally have only two positions, either fully open or fully closed. In the fully open or dispensing position, the contents of the container can be dispensed at a fixed rate dictated by the open position structure of the closure. In the fully closed position, the contents are sealed within the container and cannot be dispensed therefrom. There are dispensing closures which have a wide variety of metered dispensing openings. Typically, these closures are complex in configuration, and do not lend themselves to be formed economically by molding process, or are too fragile to be used repeatedly without failure, or both.
Additionally, existing closure caps, whether they are the two-position or the variable dispensing type, may not provide an indication to the user of the position of the closure cap. An example of these existing closure caps is shown in co-pending U.S. patent application Ser. No. 169,603 filed Mar. 17, 1988 entitled "Adjustable Metering Closure Cap" (hereinafter called "related application") which is hereby incorporated by reference, both of said applications being in the name of the same Applicant and having the same Assignee.
Thus, in these existing closure caps, in order to determine a given position of the closure cap, the user must either visually inspect or physically test the closure cap. If the closure cap is not in the desired position, the user must readjust the closure cap and visually inspect or test again. This process may need to be repeated several times before the desired dispensing position is reached.
Not only is this process tiresome and inefficient, but it can lead to unexpected volume dispensing which can be damaging, especially if the contents of the container are harmful. For example, if the closure cap is assumed to be fully closed on its container but in fact is slightly open, and the container thereafter is stored or transported, the contents can leak out with detrimental results. Additionally, if the closure cap is assumed to be slightly open for only a small amount of the contents of the container to be dispensed, but is in fact more open than expected, the contents can be displaced too quickly which again may be detrimental.
Furthermore, if a positive indication is not provided that the closure cap is in its fully open or fully closed position, or both, a user frequently attempts to move the closure cap beyond its intended fully open or fully closed position. This is true with either the push-pull type of closure cap or the threaded screw type of cap and can lead to failure of the closure cap or its removal from the container.
Dispensing the contents of a container can also be a problem when the position, and thus the flow rate of the closure cap, is changed inadvertently either before or during dispensing. This change can be caused, for example, by the flow of material through the closure or by bumping the closure against another object.
It therefore is desirable to provide a dispensing closure cap which has more than one dispensing position and provides positive indications of the cap position during manipulation thereof. It also is desirable to provide such a dispensing closure cap which cannot be opened beyond its fully open position, reduces the risk of inadvertent adjustment of the closure, is simple in design, can be readily molded with a minimum number of parts, and is sturdy in construction for repeated use without failure.